With the code cleanup in
7a6b2896f261894dde287d3faefa4b432cddca53 is the first bad commit commit 7a6b2896f261894dde287d3faefa4b432cddca53 Author: Daniel Vetter daniel.vetter@ffwll.ch Date: Fri Jul 2 15:02:15 2010 +0100
drm_mm: extract check_free_mm_node
I've botched up the range-restriction checks. The result is usually an X server dying with SIGBUS in libpixman (software fallback rendering). Change the code to adjust the start and end for range restricted allocations. IMHO this even makes the code a bit clearer.
Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_mm.c | 24 ++++++++++++++---------- 1 files changed, 14 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c index da99edc..a6bfc30 100644 --- a/drivers/gpu/drm/drm_mm.c +++ b/drivers/gpu/drm/drm_mm.c @@ -285,21 +285,21 @@ void drm_mm_put_block(struct drm_mm_node *cur)
EXPORT_SYMBOL(drm_mm_put_block);
-static int check_free_mm_node(struct drm_mm_node *entry, unsigned long size, - unsigned alignment) +static int check_free_hole(unsigned long start, unsigned long end, + unsigned long size, unsigned alignment) { unsigned wasted = 0;
- if (entry->size < size) + if (end - start < size) return 0;
if (alignment) { - register unsigned tmp = entry->start % alignment; + unsigned tmp = start % alignment; if (tmp) wasted = alignment - tmp; }
- if (entry->size >= size + wasted) { + if (end >= start + size + wasted) { return 1; }
@@ -320,7 +320,8 @@ struct drm_mm_node *drm_mm_search_free(const struct drm_mm *mm, best_size = ~0UL;
list_for_each_entry(entry, &mm->free_stack, free_stack) { - if (!check_free_mm_node(entry, size, alignment)) + if (!check_free_hole(entry->start, entry->start + entry->size, + size, alignment)) continue;
if (!best_match) @@ -353,10 +354,12 @@ struct drm_mm_node *drm_mm_search_free_in_range(const struct drm_mm *mm, best_size = ~0UL;
list_for_each_entry(entry, &mm->free_stack, free_stack) { - if (entry->start > end || (entry->start+entry->size) < start) - continue; + unsigned long adj_start = entry->start < start ? + start : entry->start; + unsigned long adj_end = entry->start + entry->size > end ? + end : entry->start + entry->size;
- if (!check_free_mm_node(entry, size, alignment)) + if (!check_free_hole(adj_start, adj_end, size, alignment)) continue;
if (!best_match) @@ -449,7 +452,8 @@ int drm_mm_scan_add_block(struct drm_mm_node *node) node->free_stack.prev = prev_free; node->free_stack.next = next_free;
- if (check_free_mm_node(node, mm->scan_size, mm->scan_alignment)) { + if (check_free_hole(node->start, node->start + node->size, + mm->scan_size, mm->scan_alignment)) { mm->scan_hit_start = node->start; mm->scan_hit_size = node->size;